Reverse engineering framework in Python
Table of Contents
- What is Miasm?
- Basic examples
- How does it work?
- Documentation
- Obtaining Miasm
- Testing
- They already use Miasm
- Misc
Miasm is a free and open source (GPLv2) reverse engineering framework. Miasm aims to analyze / modify / generate binary programs. Here is a non exhaustive list of features:
- Opening / modifying / generating PE / ELF 32 / 64 LE / BE using Elfesteem
- Assembling / Disassembling X86 / ARM / MIPS / SH4 / MSP430
- Representing assembly semantic using intermediate language
- Emulating using JIT (dynamic code analysis, unpacking, ...)
- Expression simplification for automatic de-obfuscation
- ...
See the official blog for more examples and demos.
Import Miasm x86 architecture:
>>> from miasm2.arch.x86.arch import mn_x86
>>> from miasm2.core.locationdb import LocationDBGet a location db:
>>> loc_db = LocationDB()Assemble a line:
>>> l = mn_x86.fromstring('XOR ECX, ECX', loc_db, 32)
>>> print l
XOR ECX, ECX
>>> mn_x86.asm(l)
['1\xc9', '3\xc9', 'g1\xc9', 'g3\xc9']Modify an operand:
>>> l.args[0] = mn_x86.regs.EAX
>>> print l
XOR EAX, ECX
>>> a = mn_x86.asm(l)
>>> print a
['1\xc8', '3\xc1', 'g1\xc8', 'g3\xc1']Disassemble the result:
>>> print mn_x86.dis(a[0], 32)
XOR EAX, ECXUsing Machine abstraction:
>>> from miasm2.analysis.machine import Machine
>>> mn = Machine('x86_32').mn
>>> print mn.dis('\x33\x30', 32)
XOR ESI, DWORD PTR [EAX]For Mips:
>>> mn = Machine('mips32b').mn
>>> print mn.dis('97A30020'.decode('hex'), "b")
LHU V1, 0x20(SP)Create an instruction:
>>> machine = Machine('arml')
>>> instr = machine.mn.dis('002088e0'.decode('hex'), 'l')
>>> print instr
ADD R2, R8, R0Create an intermediate representation object:
>>> ira = machine.ira(loc_db)Create an empty ircfg
>>> ircfg = ira.new_ircfg()Add instruction to the pool:
>>> ira.add_instr_to_ircfg(instr, ircfg)Print current pool:
>>> for lbl, irblock in ircfg.blocks.items():
... print irblock.to_string(loc_db)
loc_0:
R2 = R8 + R0
IRDst = loc_4
Working with IR, for instance by getting side effects:
>>> for lbl, irblock in ircfg.blocks.iteritems():
... for assignblk in irblock:
... rw = assignblk.get_rw()
... for dst, reads in rw.iteritems():
... print 'read: ', [str(x) for x in reads]
... print 'written:', dst
... print
...
read: ['R8', 'R0']
written: R2
read: []
written: IRDst
Giving a shellcode:
00000000 8d4904 lea ecx, [ecx+0x4]
00000003 8d5b01 lea ebx, [ebx+0x1]
00000006 80f901 cmp cl, 0x1
00000009 7405 jz 0x10
0000000b 8d5bff lea ebx, [ebx-1]
0000000e eb03 jmp 0x13
00000010 8d5b01 lea ebx, [ebx+0x1]
00000013 89d8 mov eax, ebx
00000015 c3 ret
>>> s = '\x8dI\x04\x8d[\x01\x80\xf9\x01t\x05\x8d[\xff\xeb\x03\x8d[\x01\x89\xd8\xc3'Import the shellcode thanks to the Container abstraction:
>>> from miasm2.analysis.binary import Container
>>> c = Container.from_string(s)
>>> c
<miasm2.analysis.binary.ContainerUnknown object at 0x7f34cefe6090>Disassembling the shellcode at address 0:
>>> from miasm2.analysis.machine import Machine
>>> machine = Machine('x86_32')
>>> mdis = machine.dis_engine(c.bin_stream)
>>> asmcfg = mdis.dis_multiblock(0)
>>> for block in asmcfg.blocks:
... print block.to_string(asmcfg.loc_db)
...
loc_0
LEA ECX, DWORD PTR [ECX + 0x4]
LEA EBX, DWORD PTR [EBX + 0x1]
CMP CL, 0x1
JZ loc_10
-> c_next:loc_b c_to:loc_10
loc_10
LEA EBX, DWORD PTR [EBX + 0x1]
-> c_next:loc_13
loc_b
LEA EBX, DWORD PTR [EBX + 0xFFFFFFFF]
JMP loc_13
-> c_to:loc_13
loc_13
MOV EAX, EBX
RETInitializing the Jit engine with a stack:
>>> jitter = machine.jitter(jit_type='python')
>>> jitter.init_stack()Add the shellcode in an arbitrary memory location:
>>> run_addr = 0x40000000
>>> from miasm2.jitter.csts import PAGE_READ, PAGE_WRITE
>>> jitter.vm.add_memory_page(run_addr, PAGE_READ | PAGE_WRITE, s)Create a sentinelle to catch the return of the shellcode:
def code_sentinelle(jitter):
jitter.run = False
jitter.pc = 0
return True
>>> jitter.add_breakpoint(0x1337beef, code_sentinelle)
>>> jitter.push_uint32_t(0x1337beef)Active logs:
>>> jitter.set_trace_log()Run at arbitrary address:
>>> jitter.init_run(run_addr)
>>> jitter.continue_run()
RAX 0000000000000000 RBX 0000000000000000 RCX 0000000000000000 RDX 0000000000000000
RSI 0000000000000000 RDI 0000000000000000 RSP 000000000123FFF8 RBP 0000000000000000
zf 0000000000000000 nf 0000000000000000 of 0000000000000000 cf 0000000000000000
RIP 0000000040000000
40000000 LEA ECX, DWORD PTR [ECX+0x4]
RAX 0000000000000000 RBX 0000000000000000 RCX 0000000000000004 RDX 0000000000000000
RSI 0000000000000000 RDI 0000000000000000 RSP 000000000123FFF8 RBP 0000000000000000
zf 0000000000000000 nf 0000000000000000 of 0000000000000000 cf 0000000000000000
....
4000000e JMP loc_0000000040000013:0x40000013
RAX 0000000000000000 RBX 0000000000000000 RCX 0000000000000004 RDX 0000000000000000
RSI 0000000000000000 RDI 0000000000000000 RSP 000000000123FFF8 RBP 0000000000000000
zf 0000000000000000 nf 0000000000000000 of 0000000000000000 cf 0000000000000000
RIP 0000000040000013
40000013 MOV EAX, EBX
RAX 0000000000000000 RBX 0000000000000000 RCX 0000000000000004 RDX 0000000000000000
RSI 0000000000000000 RDI 0000000000000000 RSP 000000000123FFF8 RBP 0000000000000000
zf 0000000000000000 nf 0000000000000000 of 0000000000000000 cf 0000000000000000
RIP 0000000040000013
40000015 RET
>>>
Interacting with the jitter:
>>> jitter.vm
ad 1230000 size 10000 RW_ hpad 0x2854b40
ad 40000000 size 16 RW_ hpad 0x25e0ed0
>>> hex(jitter.cpu.EAX)
'0x0L'
>>> jitter.cpu.ESI = 12Initializing the IR pool:
>>> ira = machine.ira()
>>> ircfg = ira.new_ircfg_from_asmcfg(asmcfg)Initializing the engine with default symbolic values:
>>> from miasm2.ir.symbexec import SymbolicExecutionEngine
>>> sb = SymbolicExecutionEngine(ira)Launching the execution:
>>> symbolic_pc = sb.run_at(ircfg, 0)
>>> print symbolic_pc
((ECX + 0x4)[0:8] + 0xFF)?(0xB,0x10)Same, with step logs (only changes are displayed):
>>> sb = SymbolicExecutionEngine(ira, machine.mn.regs.regs_init)
>>> symbolic_pc = sb.run_at(ircfg, 0, step=True)
Instr LEA ECX, DWORD PTR [ECX + 0x4]
Assignblk:
ECX = ECX + 0x4
________________________________________________________________________________
ECX = ECX + 0x4
________________________________________________________________________________
Instr LEA EBX, DWORD PTR [EBX + 0x1]
Assignblk:
EBX = EBX + 0x1
________________________________________________________________________________
EBX = EBX + 0x1
ECX = ECX + 0x4
________________________________________________________________________________
Instr CMP CL, 0x1
Assignblk:
zf = (ECX[0:8] + -0x1)?(0x0,0x1)
nf = (ECX[0:8] + -0x1)[7:8]
pf = parity((ECX[0:8] + -0x1) & 0xFF)
of = ((ECX[0:8] ^ (ECX[0:8] + -0x1)) & (ECX[0:8] ^ 0x1))[7:8]
cf = (((ECX[0:8] ^ 0x1) ^ (ECX[0:8] + -0x1)) ^ ((ECX[0:8] ^ (ECX[0:8] + -0x1)) & (ECX[0:8] ^ 0x1)))[7:8]
af = ((ECX[0:8] ^ 0x1) ^ (ECX[0:8] + -0x1))[4:5]
________________________________________________________________________________
af = (((ECX + 0x4)[0:8] + 0xFF) ^ (ECX + 0x4)[0:8] ^ 0x1)[4:5]
pf = parity((ECX + 0x4)[0:8] + 0xFF)
zf = ((ECX + 0x4)[0:8] + 0xFF)?(0x0,0x1)
ECX = ECX + 0x4
of = ((((ECX + 0x4)[0:8] + 0xFF) ^ (ECX + 0x4)[0:8]) & ((ECX + 0x4)[0:8] ^ 0x1))[7:8]
nf = ((ECX + 0x4)[0:8] + 0xFF)[7:8]
cf = (((((ECX + 0x4)[0:8] + 0xFF) ^ (ECX + 0x4)[0:8]) & ((ECX + 0x4)[0:8] ^ 0x1)) ^ ((ECX + 0x4)[0:8] + 0xFF) ^ (ECX + 0x4)[0:8] ^ 0x1)[7:8]
EBX = EBX + 0x1
________________________________________________________________________________
Instr JZ loc_key_1
Assignblk:
IRDst = zf?(loc_key_1,loc_key_2)
EIP = zf?(loc_key_1,loc_key_2)
________________________________________________________________________________
af = (((ECX + 0x4)[0:8] + 0xFF) ^ (ECX + 0x4)[0:8] ^ 0x1)[4:5]
EIP = ((ECX + 0x4)[0:8] + 0xFF)?(0xB,0x10)
pf = parity((ECX + 0x4)[0:8] + 0xFF)
IRDst = ((ECX + 0x4)[0:8] + 0xFF)?(0xB,0x10)
zf = ((ECX + 0x4)[0:8] + 0xFF)?(0x0,0x1)
ECX = ECX + 0x4
of = ((((ECX + 0x4)[0:8] + 0xFF) ^ (ECX + 0x4)[0:8]) & ((ECX + 0x4)[0:8] ^ 0x1))[7:8]
nf = ((ECX + 0x4)[0:8] + 0xFF)[7:8]
cf = (((((ECX + 0x4)[0:8] + 0xFF) ^ (ECX + 0x4)[0:8]) & ((ECX + 0x4)[0:8] ^ 0x1)) ^ ((ECX + 0x4)[0:8] + 0xFF) ^ (ECX + 0x4)[0:8] ^ 0x1)[7:8]
EBX = EBX + 0x1
________________________________________________________________________________
>>>Retry execution with a concrete ECX. Here, the symbolic / concolic execution reach the shellcode's end:
>>> from miasm2.expression.expression import ExprInt
>>> sb.symbols[machine.mn.regs.ECX] = ExprInt(-3)
>>> symbolic_pc = sb.run_at(ircfg, 0, step=True)
Instr LEA ECX, DWORD PTR [ECX + 0x4]
Assignblk:
ECX = ECX + 0x4
________________________________________________________________________________
af = (((ECX + 0x4)[0:8] + 0xFF) ^ (ECX + 0x4)[0:8] ^ 0x1)[4:5]
EIP = ((ECX + 0x4)[0:8] + 0xFF)?(0xB,0x10)
pf = parity((ECX + 0x4)[0:8] + 0xFF)
IRDst = ((ECX + 0x4)[0:8] + 0xFF)?(0xB,0x10)
zf = ((ECX + 0x4)[0:8] + 0xFF)?(0x0,0x1)
ECX = 0x1
of = ((((ECX + 0x4)[0:8] + 0xFF) ^ (ECX + 0x4)[0:8]) & ((ECX + 0x4)[0:8] ^ 0x1))[7:8]
nf = ((ECX + 0x4)[0:8] + 0xFF)[7:8]
cf = (((((ECX + 0x4)[0:8] + 0xFF) ^ (ECX + 0x4)[0:8]) & ((ECX + 0x4)[0:8] ^ 0x1)) ^ ((ECX + 0x4)[0:8] + 0xFF) ^ (ECX + 0x4)[0:8] ^ 0x1)[7:8]
EBX = EBX + 0x1
________________________________________________________________________________
Instr LEA EBX, DWORD PTR [EBX + 0x1]
Assignblk:
EBX = EBX + 0x1
________________________________________________________________________________
af = (((ECX + 0x4)[0:8] + 0xFF) ^ (ECX + 0x4)[0:8] ^ 0x1)[4:5]
EIP = ((ECX + 0x4)[0:8] + 0xFF)?(0xB,0x10)
pf = parity((ECX + 0x4)[0:8] + 0xFF)
IRDst = ((ECX + 0x4)[0:8] + 0xFF)?(0xB,0x10)
zf = ((ECX + 0x4)[0:8] + 0xFF)?(0x0,0x1)
ECX = 0x1
of = ((((ECX + 0x4)[0:8] + 0xFF) ^ (ECX + 0x4)[0:8]) & ((ECX + 0x4)[0:8] ^ 0x1))[7:8]
nf = ((ECX + 0x4)[0:8] + 0xFF)[7:8]
cf = (((((ECX + 0x4)[0:8] + 0xFF) ^ (ECX + 0x4)[0:8]) & ((ECX + 0x4)[0:8] ^ 0x1)) ^ ((ECX + 0x4)[0:8] + 0xFF) ^ (ECX + 0x4)[0:8] ^ 0x1)[7:8]
EBX = EBX + 0x2
________________________________________________________________________________
Instr CMP CL, 0x1
Assignblk:
zf = (ECX[0:8] + -0x1)?(0x0,0x1)
nf = (ECX[0:8] + -0x1)[7:8]
pf = parity((ECX[0:8] + -0x1) & 0xFF)
of = ((ECX[0:8] ^ (ECX[0:8] + -0x1)) & (ECX[0:8] ^ 0x1))[7:8]
cf = (((ECX[0:8] ^ 0x1) ^ (ECX[0:8] + -0x1)) ^ ((ECX[0:8] ^ (ECX[0:8] + -0x1)) & (ECX[0:8] ^ 0x1)))[7:8]
af = ((ECX[0:8] ^ 0x1) ^ (ECX[0:8] + -0x1))[4:5]
________________________________________________________________________________
af = 0x0
EIP = ((ECX + 0x4)[0:8] + 0xFF)?(0xB,0x10)
pf = 0x1
IRDst = ((ECX + 0x4)[0:8] + 0xFF)?(0xB,0x10)
zf = 0x1
ECX = 0x1
of = 0x0
nf = 0x0
cf = 0x0
EBX = EBX + 0x2
________________________________________________________________________________
Instr JZ loc_key_1
Assignblk:
IRDst = zf?(loc_key_1,loc_key_2)
EIP = zf?(loc_key_1,loc_key_2)
________________________________________________________________________________
af = 0x0
EIP = 0x10
pf = 0x1
IRDst = 0x10
zf = 0x1
ECX = 0x1
of = 0x0
nf = 0x0
cf = 0x0
EBX = EBX + 0x2
________________________________________________________________________________
Instr LEA EBX, DWORD PTR [EBX + 0x1]
Assignblk:
EBX = EBX + 0x1
________________________________________________________________________________
af = 0x0
EIP = 0x10
pf = 0x1
IRDst = 0x10
zf = 0x1
ECX = 0x1
of = 0x0
nf = 0x0
cf = 0x0
EBX = EBX + 0x3
________________________________________________________________________________
Instr LEA EBX, DWORD PTR [EBX + 0x1]
Assignblk:
IRDst = loc_key_3
________________________________________________________________________________
af = 0x0
EIP = 0x10
pf = 0x1
IRDst = 0x13
zf = 0x1
ECX = 0x1
of = 0x0
nf = 0x0
cf = 0x0
EBX = EBX + 0x3
________________________________________________________________________________
Instr MOV EAX, EBX
Assignblk:
EAX = EBX
________________________________________________________________________________
af = 0x0
EIP = 0x10
pf = 0x1
IRDst = 0x13
zf = 0x1
ECX = 0x1
of = 0x0
nf = 0x0
cf = 0x0
EBX = EBX + 0x3
EAX = EBX + 0x3
________________________________________________________________________________
Instr RET
Assignblk:
IRDst = @32[ESP[0:32]]
ESP = {ESP[0:32] + 0x4 0 32}
EIP = @32[ESP[0:32]]
________________________________________________________________________________
af = 0x0
EIP = @32[ESP]
pf = 0x1
IRDst = @32[ESP]
zf = 0x1
ECX = 0x1
of = 0x0
nf = 0x0
cf = 0x0
EBX = EBX + 0x3
ESP = ESP + 0x4
EAX = EBX + 0x3
________________________________________________________________________________
>>>Miasm embeds its own disassembler, intermediate language and instruction semantic. It is written in Python.
To emulate code, it uses LLVM, GCC, Clang or Python to JIT the intermediate representation. It can emulate shellcodes and all or parts of binaries. Python callbacks can be executed to interact with the execution, for instance to emulate library functions effects.
TODO
An auto-generated documentation is available here.
- Clone the repository: Miasm on GitHub
- Get one of the Docker images at Docker Hub
Miasm uses:
- python-pyparsing
- python-dev
- elfesteem from Elfesteem
- optionally python-pycparser (version >= 2.17)
To enable code JIT, one of the following module is mandatory:
- GCC
- Clang
- LLVM with Numba llvmlite, see below
'optional' Miasm can also use:
- Z3, the Theorem Prover
- Install elfesteem
git clone https://github.com/serpilliere/elfesteem.git elfesteem
cd elfesteem
python setup.py build
sudo python setup.py installTo use the jitter, GCC or LLVM is recommended
- GCC (any version)
- Clang (any version)
- LLVM
- Debian (testing/unstable): Not tested
- Debian stable/Ubuntu/Kali/whatever:
pip install llvmliteor install from llvmlite - Windows: Not tested
- Build and install Miasm:
$ cd miasm_directory
$ python setup.py build
$ sudo python setup.py installIf something goes wrong during one of the jitter modules compilation, Miasm will skip the error and disable the corresponding module (see the compilation output).
Most of Miasm's IDA plugins use a subset of Miasm functionnality. A quick way to have them working is to add:
elfesteemdirectory andpyparsing.pytoC:\...\IDA\python\orpip install pyparsing elfesteemmiasm2/miasm2directory toC:\...\IDA\python\
All features excepting JITter related ones will be available. For a more complete installation, please refer to above paragraphs.
Miasm comes with a set of regression tests. To run all of them:
cd miasm_directory/test
python test_all.pySome options can be specified:
- Mono threading:
-m - Code coverage instrumentation:
-c - Only fast tests:
-t long(excludes the long tests)
- Sibyl: A function divination too
- R2M2: Use miasm2 as a radare2 plugin
- CGrex : Targeted patcher for CGC binaries
- ethRE Reversing tool for Ethereum EVM (with corresponding Miasm2 architecture)
- Deobfuscation: recovering an OLLVM-protected program
- Taming a Wild Nanomite-protected MIPS Binary With Symbolic Execution: No Such Crackme
- Génération rapide de DGA avec Miasm: Quick computation of DGA (French article)
- Enabling Client-Side Crash-Resistance to Overcome Diversification and Information Hiding: Detect undirected call potential arguments
- Miasm: Framework de reverse engineering (French)
- Tutorial miasm (French video)
- Graphes de dépendances : Petit Poucet style: DepGraph (French)
- Practical Reverse Engineering: X86, X64, Arm, Windows Kernel, Reversing Tools, and Obfuscation: Introduction to Miasm (Chapter 5 "Obfuscation")
- BlackHat Python - Appendix: Japan security book's samples
- Man, does miasm has a link with rr0d?
- Yes! crappy code and uggly documentation.